Conventionally known is an horizontally articulated robot for transferring semiconductor wafers between a FOUP (Front Open Unified Pod) and a semiconductor processing device (Patent reference 1, for example). A horizontally articulated robot disclosed in Patent reference 1 configures part of an EFEM (Equipment Front End side Module) and is arranged inside an EFEM housing. The EFEM is arranged on the front side of the semiconductor processor while the FOUP is arranged on the front side of the EFEM. The EFEM housing is formed in a rectangular box which has its shorter-length direction in the front-rear direction and its longer-length direction in the left-right direction.
The horizontally articulated robot disclosed in Patent reference 1 is provided with two hands on which semiconductor wafers are to be mounted, an arm to which the two hands are rotatably joined to the front end side thereof, and a main body portion to which the base end side of the arm is rotatably joined. The arm is configured by a first arm portion, of which the base end side is rotatably joined to the main body portion, a second arm portion, of which the base end side is rotatably joined to the front end side of the first arm portion, and a third arm portion, of which the base end side is rotatably joined to the front end side of the second arm portion and to which the hands are rotatably attached to the front end side thereof. The main body portion is provided with a column member, to which the base end side of the arm (that is, the base end side of the first arm portion) is rotatably joined to the top end thereof, a housing which holds the column member to be able to elevate, and an elevating mechanism which raises/lowers the column member. The column member is housed in the housing when lowered. Also, the elevating mechanism is housed inside the housing. Even when the column member is elevated, the bottom portion of the column member is inside the housing.
The housing is formed such that the shape thereof is square when viewed from the top-bottom direction; the front and rear surfaces of the housing are formed to be planar and intersect orthogonally with the front-rear direction; the left and right surfaces of the housing are formed to be planar and intersect orthogonally with the left-right direction. When viewed from the top-bottom direction, the column member is inside the outward form of the housing. When viewed from the top-bottom direction, the column member is in the center position in the left-right direction of the housing. Also, the column member is on the front side of the housing in the front-rear direction when viewed from the top-bottom direction. In other words, the base end side of the arm joined to the column member is positioned on the front side of the housing.
The horizontally articulated robot disclosed in Patent reference 1 is arranged in the EFEM housing such that the inside front surface of the EFEM housing is adjacent to the front surface of the housing of the horizontally articulated robot. In other words, the horizontally articulated robot is positioned inside the EFEM housing such that the base end side of the arm joined to the column member is adjacent to the inside front surface of the EFEM housing. For this reason, in an semiconductor fabrication system in which the horizontally articulated root is installed, it is possible to prevent the interference between the inside front and rear surfaces of the EFEM housing and the arm while ensuring the lengths of the first arm portion, the second arm portion and the third arm portion.